The discovery of topological defects in amorphous systems and the prediction of the yielding point using the Burgers vector [Jul. 06, 2021]

In a recent PRL publication ( ), a research team led by professor Matteo Baggioli from SJTU Shanghai and professor Alessio Zaccone from University of Milano, discovered, for the first time, well-defined topological defects in amorphous solids by analyzing the topological structure of the dynamical displacement field under deformation. This new description based on topological higher-form symmetries quantifies the amount of non-affine displacements at the atomic/molecular level and uses it as a topological predictor of plastic events using the geometrical concept of dynamical Burgers vector. The new theory provides a very accurate prediction for the yielding point at the plasticity transition of amorphous solids, and explains the occurrence of shear bands ubiquitously observed in experiments.